cm-t54: add cm-t54 board support

Add cm-t54 board directory, config file. Enable build.

Basic support includes:

Serial console
SD/MMC
eMMC
USB
Ethernet

Signed-off-by: Dmitry Lifshitz <lifshitz@compulab.co.il>
Acked-by: Igor Grinberg <grinberg@compulab.co.il>
6 files changed